阅读说明：本技术 保温钢包包盖专用浇注料以及包盖制造方法 (Pouring material special for ladle cover of heat-preservation ladle and manufacturing method of ladle cover ) 是由 侯会峰 侯振东 刘大圈 于 2021-04-02 设计创作，主要内容包括：本发明公开了一种保温钢包包盖专用浇注料以及包盖制造方法,浇注料是由一级高铝矾土熟料70%(粒度10-6mm的颗粒料15%,粒度6-3mm的颗粒料25%,粒度3-1mm的颗粒料15%,粒度1-0mm的颗粒料15%),尖晶石粉5%,一级铝粉16%,电熔镁粉2%,金属铝粉0.5%,Na-2HCO-(3 )0.4%,偶氮酰胺1%,塞卡71水泥3%,九水偏硅酸钠2%,防爆纤维0.1%配制而成。使用时,将上述原料准确称量并预混均匀后,按混合料总重的7%加水搅拌成浇注料,浇注在包盖模型中预制成型,经常温养护24小时后,即得到包盖成品。本发明浇注成型后无需烘烤,自然干燥即可快速排除水分,包盖遇高温更坚固,不裂纹、不剥落,耐高温侵袭、抗热震,可适应钢包高温变化；使用寿命是普通包盖的2倍,节约了材料成本。(The invention discloses a castable special for a ladle cover of a heat-preservation ladle and a manufacturing method of the ladle cover, wherein the castable is prepared from 70% of first-grade high-alumina bauxite clinker (15% of granules with the granularity of 10-6mm, 25% of granules with the granularity of 6-3mm, 15% of granules with the granularity of 3-1mm, 15% of granules with the granularity of 1-0 mm), 5% of spinel powder, 16% of first-grade aluminum powder, 2% of fused magnesia powder, 0.5% of metal aluminum powder, and Na 2 HCO 3 0.4 percent of azoamide, 1 percent of cement, 3 percent of Seka 71, 2 percent of sodium metasilicate nonahydrate and 0.1 percent of explosion-proof fiber. When in use, the raw materials are accurately weighed and premixed uniformly, and then added according to 7 percent of the total weight of the mixtureStirring the mixture with water to form a casting material, casting the casting material in a ladle cover model for prefabrication and molding, and curing at normal temperature for 24 hours to obtain a finished ladle cover product. The invention can quickly remove water by natural drying without baking after casting and molding, the ladle cover is firmer in high temperature, does not crack or peel off, resists high-temperature invasion and thermal shock, and can adapt to the high-temperature change of the ladle; the service life of the bag cover is 2 times that of the common bag cover, and the material cost is saved.)

1. The special castable for the heat-preservation ladle cover is characterized by comprising the following components in parts by weight: is prepared from raw materials of first-grade high-alumina bauxite clinker, spinel powder, first-grade aluminum powder, fused magnesium powder, metal aluminum powder and Na₂HCO₃The azoamide, the saika 71 cement, the sodium metasilicate nonahydrate and the explosion-proof fiber are prepared according to the following weight percentage:

70% of first-grade high-bauxite clinker, wherein: 15% of granules with the granularity of 10-6mm, 25% of granules with the granularity of 6-3mm, 15% of granules with the granularity of 3-1mm and 15% of granules with the granularity of 1-0 mm;

5% of spinel powder;

16 percent of first-grade aluminum powder

2% of fused magnesium powder;

0.5 percent of metal aluminum powder;

Na₂HCO₃ 0.4%；

1% of azoamide;

the saika 71 cement is 3 percent;

2 percent of sodium metasilicate nonahydrate

0.1 percent of explosion-proof fiber.

2. The castable special for the heat-preservation ladle cover according to claim 1, characterized in that: the above-mentionedAl in first-grade high-bauxite clinker₂O₃Not less than 85%, volume density > 3.10g/cm³。

3. The castable special for the heat-preservation ladle cover according to claim 1, characterized in that: al in the spinel powder₂O₃≧ 70%, MgO ≧ 25%; the fineness of the first-grade aluminum powder is 180 meshes and Al₂O₃Not less than 80%; the fineness of the fused magnesium powder is 180 meshes, and MgO is not less than 97%; the fineness of the metal aluminum powder is 100 meshes and Al₂O₃≧99%。

4. A manufacturing method of a heat preservation ladle cover is characterized in that:

firstly, accurately weighing the raw materials according to the raw material proportion of claim 1, uniformly stirring and mixing, adding 7% of water, stirring and mixing to form a castable, pouring the castable in a ladle cover model, and performing prefabrication and molding;

and step two, curing for 24 hours at normal temperature to obtain a finished product of the ladle cover.

Technical Field

The invention relates to a high-temperature molten iron transfer container-ladle, in particular to a special castable for a heat-preservation ladle cover, and also relates to a manufacturing method of the ladle cover.

Background

The ladle is a transfer vessel for transporting high-temperature molten steel from a converter or an electric furnace to a continuous casting machine, and simultaneously takes on the task of secondary external refining. Because a large amount of heat is dissipated and lost in the lifting and refining processes, the tapping temperature of molten steel or the temperature during refining needs to be increased during transportation. In order to reduce heat loss, most steel mills begin to add ladle covers on the ladles to prevent the loss of molten steel due to temperature dissipation.

In the transfer process, the ladle cover is not contacted with molten steel, but is subjected to the attack of the high-temperature environment of the molten steel and high-temperature gas on the ladle cover, the temperature can reach over 1200 ℃ at the highest temperature, and the ladle cover is also subjected to rapid temperature change, so that the castable of the inner layer of the ladle cover is required to have the characteristics of high temperature resistance, high strength, difficult shedding, good thermal shock resistance and the like.

Because the position of use and environment are comparatively special, current ladle be built by the pouring material and is moulded, use after toasting again, its toast the curve requirement and be: the castable is maintained at normal temperature for 24 hours, then is baked for 12-24 hours after being heated from the normal temperature to 500 ℃, and finally is baked for 6-12 hours after being heated from 500 ℃ to 800 ℃, the total time is about 60 hours, if the baking time is short or the temperature is too high, the moisture in the castable is not discharged in time, and the phenomenon that the covering material falls off or bursts due to too high water vapor pressure occurs. Meanwhile, the adopted high-temperature resistant material is not resistant to the invasion of ladle temperature gas, so that cracks and falling are very easy to occur, the service life is short, and the using effect is very poor.

Disclosure of Invention

The invention aims to provide a castable special for a heat-preservation ladle cover, which has long service life and can meet the use requirement of a ladle, and a manufacturing method of the heat-preservation ladle cover.

In order to achieve the purpose, the invention can adopt the following technical scheme:

the invention relates to a special castable for a heat-preservation ladle cover, which is prepared from raw materials of first-grade high-alumina bauxite clinker, spinel powder, first-grade aluminum powder, fused magnesia powder, metal aluminum powder and Na₂HCO₃Azoamide, saika 71 cement and sodium metasilicate nonahydrateAnd the explosion-proof fiber is prepared by the following weight percentage:

70% of first-grade high-bauxite clinker, wherein: 15% of granules with the granularity of 10-6mm, 25% of granules with the granularity of 6-3mm, 15% of granules with the granularity of 3-1mm and 15% of granules with the granularity of 1-0 mm;

5% of spinel powder;

16 percent of first-grade aluminum powder

2% of fused magnesium powder;

0.5 percent of metal aluminum powder;

Na₂HCO₃ 0.4%；

1% of azoamide;

the saika 71 cement is 3 percent;

2 percent of sodium metasilicate nonahydrate

0.1 percent of explosion-proof fiber.

In order to ensure the quality requirement of the castable, Al in the first-grade high-alumina bauxite clinker is used₂O₃Not less than 85%, volume density > 3.10g/cm³。

Al in the spinel powder₂O₃≧ 70%, MgO ≧ 25%; the fineness of the first-grade aluminum powder is 180 meshes and Al₂O₃Not less than 80%; the fineness of the fused magnesium powder is 180 meshes, and MgO is not less than 97%; the fineness of the metal aluminum powder is 100 meshes and Al₂O₃≧99%。

The manufacturing method of the heat preservation ladle cover comprises the following steps:

firstly, accurately weighing the raw materials according to the raw material proportion designed by the invention, uniformly stirring and mixing, adding water accounting for 7 percent of the total weight of the raw materials, stirring and mixing to form a castable, and pouring the castable in a ladle cover model for prefabrication and molding;

secondly, curing at normal temperature for 24 hours to obtain a finished product of the ladle cover; the detection shows that the physical and chemical indexes of the finished product ladle cover are as follows:

the castable special for the ladle cover adopts the first-grade high alumina bauxite as the framework, and has high strength, high refractoriness and stable volume; the fused magnesia powder is used as an expanding agent, and the magnesia powder and the first-grade aluminum powder are mixed at high temperatureThe generated spinel has a certain expansion amount to make up for shrinkage cracks of the castable; the cement Saka 71 and the sodium metasilicate nonahydrate are used as a bonding agent to generate higher strength, and the metal aluminum powder and Na are used₂HCO_3、The explosion-proof fiber increases the porosity to open a hydrophobic channel of the castable; azoamide is used as a foaming agent, so that closed pores can be increased, the volume density can be reduced, and the heat insulation performance of the castable can be improved.

The invention has the advantages that:

1. after casting molding, baking is not needed, moisture can be quickly removed by natural drying, and the manufacturing method is simple;

2. the formed ladle cover is firmer in high temperature, does not crack or peel off, resists high-temperature invasion and thermal shock, and is suitable for the high-temperature change of the ladle.

3. Tests prove that the service life of the ladle cover produced by the invention is 2 times of that of a common ladle cover, the material cost is saved, the energy consumption is reduced, and the benefit is improved.

Detailed Description

The present invention is described in more detail below with reference to specific examples to facilitate understanding for those skilled in the art.

The raw materials used by the invention are bauxite chamotte, spinel powder, first-grade aluminum powder, fused magnesium powder, metal aluminum powder and Na₂HCO₃The azoamide, the saika 71 cement, the sodium metasilicate nonahydrate, the explosion-proof fiber and the like are all commercial products, and the adopted blenders and the like are all conventional equipment.

The special castable for the heat-preservation ladle cover is prepared according to 70 percent of first-grade bauxite chamotte (wherein the mixture ratio is according to the following grain size distribution, namely 15 percent of granular material with the grain size of 10-6mm, 25 percent of granular material with the grain size of 6-3mm, 15 percent of granular material with the grain size of 3-1mm and 15 percent of granular material with the grain size of 1-0 mm); 5% of spinel powder; 16% of first-grade aluminum powder; 2% of fused magnesium powder; 0.5 percent of metal aluminum powder; na (Na)₂HCO₃ 0.4 percent; 1% of azoamide; the saika 71 cement is 3 percent; 2% of sodium metasilicate nonahydrate; 0.1 percent of explosion-proof fiber; when in use, the raw materials are accurately weighed and premixed uniformly, then water is added according to 7 percent of the total weight of the mixture to be stirred into a pouring material, the pouring material is poured into a ladle cover model for prefabrication forming, and the pouring material is often warmed to be curedProtecting for 24 hours to obtain the finished product of the ladle cover.

The special castable for the ladle cover of the heat-preservation ladle prepared by the invention is used on a 60-ton ladle in Hebei Puyang iron and steel works, the service life of the castable can reach more than 300 furnaces, and the service life of the castable is twice of that of a common ladle cover material. Long service life and good heat preservation effect, does not need baking, and can be used on line after being cured at normal temperature.

The original covering material has low high-temperature strength, slight vibration in the transportation process and the turning process of the steel ladle due to low high-temperature strength, and corrosion and impact of high-temperature gas easily cause the falling and damage of the covering material, and the covering material is off-line for maintenance when used in about 150 furnaces; in 2020, the special ladle cover castable prepared by the method is used, and a 310 furnace is used on line under the condition of no baking, so that the phenomena of falling and block falling do not occur in the middle process, and the using effect is good.